Hello everybody and welcome back in this election we are going to talk about constraining the K the
inversed kinematics because when you apply auto I k to any of your rigs you will find that it ignores
the bone constraints you have currently put in.
Now this can be a little bit infuriating but when you set something up it's absolutely fine to have
those bone constraints in place.
In fact if we have a quick look at the bone rates on any of the bones that are green that means they've
got a bone constraint on them to grow to the bone itself.
Sorry next tab along the bone constraints and select one of those.
We actually have some values that we've gone ahead and set up and we can reuse those when we want to.
And we've got minus 45 as a minimum and 120 is.
In fact I'm going to make this a little wider so we can see everything and dismiss salthill shelford
properties panel and clay.
So how do we go ahead and constrain the movement of the AK.
Because at the moment we can do all sorts of stuff that breaks the rules that we had before.
The only thing we do have going is if we go to the bone itself we have put a transform lock and that
does help in its movement somewhat and prevents.
That's to say it moving in the wrong place.
So we have got some control over there that does stick in place but we want it to be a bit more controlled
in terms of the case.
Now we do that under the bone tab or it's each bone individually and we scroll down and we need to be
imposed modes he will need to make sure you are in Post mode and there is a tab called inverse kinematics.
Now when we go to that we will see that it is greyed out and that can be a little bit annoying at first.
We start getting there.
But what we need to do in order to bring that back is we need to add a different type of constraint
to the bone.
So we'll focus on this top one here at the moment.
So going to add a bone constraint and inverse kinematics.
Now we're not going to touch any of the other points in here at the moment but what we can now do is
go back to the bone and we can see the inverse kinematics is now basically not greyed out.
We can start changing things so we can put a limit on the movement of X Y and Z if we want and we see
we get a pretty pattern starting to appear.
Now we don't know quite at the moment which ones were going to be limiting or locking down on preventing
movement on and we can do trial and error if we want and we can see here that we do have this sort of
envelope that's come around our our shade here our lampshade and it tells us how far we're going to
be able to move it.
Now in order to do this instead of just moving the head itself off the lamp we often go ahead here and
just press after rotate then we can see it can pretty much move around freely.
We don't want it to do that we don't want it to go backwards on itself.
So let's go ahead here.
This is a crazy amount of movement.
It's got something to set it's zero and zero on X Y and Z.
I'm just using habits of go through these fields.
So the first thing is I saw there that Z seems to go around this way.
So let's go ahead and do that let's go.
I don't know 60 degrees one way so minus 60 to 60 and that gives us a blue arc on our screen.
Okay so what was the other way if a fossil red there which would be x.
Let's do this from minus 60 to 60 as well.
Now I go ahead and move it about we can see that it no longer decides to be a bit crazy and it sticks
within its bounds as well.
We can see here I can move it along that way and bring it back.
And when it reaches a certain point it will just stop moving around and move the rest of the model itself.
And that's a good way of starting to control and constrain your movements.
Now at this point we could because we're not using it just lock the y axis all together.
If we were to lock the x and z axis it would just move as one solid part as we can see here.
Now you can also increase the stiffness.
And this is the amounts that it will move everything else so we work the stiffness up to a value of
one which we can do.
It would be the same as locking it completely.
But we see here it still moves almost as if it was locked.
However if we lower that down it will have a dampening effect so won't move quite so freely but it will
drag everything else behind it as well which gives you a more natural movement when you do that because
it's very unlikely that you will want to move just the lampshade in this case by itself without the
rest of the body of the lamp moving along as well.
Oh and I can see one final thing here.
Have inadvertently not unchecked deform on a lampshade itself.
Something to make sure that all of that is saved and in place.
Excellent.
And now it's time for a challenge all before we go off and do that challenged just one final thing here.
I've often been playing with this and I get the lamp in a funny position and I just want to get it back
to it.
Being static again a very good way of doing that is to press the aiki twice in this case to select all
of our bones and clear the rotations and movements by going Oulton are to clear rotations Oulton to
clear movements if there are any and there we go we've got our lamp back to its starting position very
quick way of when youre playing with things just getting it back to the beginning right.
Its time for that challenge.
Okay so a nice simple challenge here I'd like you to constrain the bone so apply inversed kinematic
constraints to the rest of your bones.
Remember we've got the reference from the original bone constraints we had put on there.
Go ahead pause video and give that a go.
OK everybody welcome back.
Let's go ahead now and apply those I take constraints.
Okay so now we're back over in blender.
I'm going to have a look at the bone constrained by I had originally over in the bone and straight here.
And bear in mind that we're going to have to put an AK constraint on that as well.
So let's just have a look here.
We have limits of X minus 45 to 120 set X.
We're going to limit it to minus 45 all the way to 120 and we can see that in how far it can move forwards
and back which is great.
It's not going to be able to.
Well it's not going to be able to flatten itself out anymore.
So here and the next bone Let's go to the bone through mine and safety and 130.
And minus 80 all the way to 130.
Perfect.
We're going to limit it there.
I'm also going to lock the Y and Z because it's not going to move on those at all.
So we've got those locked out.
Now this last bone Here's a bit of an oddity.
We certainly don't want him bending or moving around but the transform locks themselves pretty much
sorted that one out.
But the one thing I have noticed is if I try and move it I get this crazy stuff happening.
Well first of all I need the base to follow with it so there's a bit of parenting to do here.
We've got the lamp base all by itself so I'm going to shift after it's been selected shift select the
lower bone here and parent it to the bone.
And that does mean that now I can move this base bone and the base will move along with it.
The other thing to bear in mind here is when we go ahead and move that headlamp does something really
weird.
It just jumps down here.
Unfortunately one of those many quirks if we grab the top here and just move it about and start moving
the bottom again.
We see that it no longer does that weird motion.
But the head does stay still because this is the very end of the case where we place this is going to
stay until it has to be dragged back further.
So that's something to bear in mind.
We could place this if it was a hand for instance on an object and then move the rest of the body towards
it if we wanted to.
So there's lots of options there.
And similarly when we drag this one out we reach an end point which we can't drag it any further.
Okay.
There we go.
Brilliant.
My constraints are all in.
Hope you've sorted out yours as well.
Looking forward to seeing how your lamps are coming on and I'll see well in the next lecture.